package  Calcuator;

import java.util.*;
import java.util.regex.Pattern;
public  class  BaseCalcuator{
        /**
         * 匹配 + - * / ( ) 运算符
         */
        static final String SYMBOL = "\\+|-|\\*|/|\\(|\\)";

        static final String LEFT = "(";
        static final String RIGHT = ")";
        static final String ADD = "+";
        static final String MINUS= "-";
        static final String TIMES = "*";
        static final String DIVISION = "/";
        static List<String> result;
    String restult;
    String math;
    /**
         * 加減 + -
         */
        static final int LEVEL_01 = 1;
        /**
         * 乘除 * /
         */
        static final int LEVEL_02 = 2;

        /**
         * 括号
         */
        static final int LEVEL_HIGH = Integer.MAX_VALUE;


        static Stack<String> stack = new Stack<>();
        static List<String> data = Collections.synchronizedList(new ArrayList<String>());

        /**
         * 去除所有空白符
         * @param s
         * @return
         */
        public static String replaceAllBlank(String s ){
            // \\s+ 匹配任何空白字符，包括空格、制表符、换页符等等, 等价于[ \f\n\r\t\v]
            return s.replaceAll("\\s+","");
        }

        /**
         * 判断是不是数字 int double long float
         * @param s
         * @return
         */
        public static boolean isNumber(String s){
            Pattern pattern = Pattern.compile("^[-\\+]?[.\\d]*$");
            return pattern.matcher(s).matches();
        }

        /**
         * 判断是不是运算符
         * @param s
         * @return
         */
        public static boolean isSymbol(String s){
            return s.matches(SYMBOL);
        }

        /**
         * 匹配运算等级
         * @param s
         * @return
         */
        public static int calcLevel(String s){
            if("+".equals(s) || "-".equals(s)){
                return LEVEL_01;
            } else if("*".equals(s) || "/".equals(s)){
                return LEVEL_02;
            }
            return LEVEL_HIGH;
        }

        /**
         * 匹配
         * @param s
         * @throws Exception
         */
        public static List<String> doMatch (String s) throws Exception{
            if(s == null || "".equals(s.trim())) throw new RuntimeException("data is empty");
            if(!isNumber(s.charAt(0)+"")) throw new RuntimeException("data illeagle,start not with a number");

            s = replaceAllBlank(s);

            String each;
            int start = 0;

            for (int i = 0; i < s.length(); i++) {
                if(isSymbol(s.charAt(i)+"")){
                    each = s.charAt(i)+"";
                    //栈为空，(操作符，或者 操作符优先级大于栈顶优先级 && 操作符优先级不是( )的优先级 及是 ) 不能直接入栈
                    if(stack.isEmpty() || LEFT.equals(each)
                            || ((calcLevel(each) > calcLevel(stack.peek())) && calcLevel(each) < LEVEL_HIGH)){
                        stack.push(each);
                    }else if( !stack.isEmpty() && calcLevel(each) <= calcLevel(stack.peek())){
                        //栈非空，操作符优先级小于等于栈顶优先级时出栈入列，直到栈为空，或者遇到了(，最后操作符入栈
                        while (!stack.isEmpty() && calcLevel(each) <= calcLevel(stack.peek()) ){
                            if(calcLevel(stack.peek()) == LEVEL_HIGH){
                                break;
                            }
                            data.add(stack.pop());
                        }
                        stack.push(each);
                    }else if(RIGHT.equals(each)){
                        // ) 操作符，依次出栈入列直到空栈或者遇到了第一个)操作符，此时)出栈
                        while (!stack.isEmpty() && LEVEL_HIGH >= calcLevel(stack.peek())){
                            if(LEVEL_HIGH == calcLevel(stack.peek())){
                                stack.pop();
                                break;
                            }
                            data.add(stack.pop());
                        }
                    }
                    start = i ;    //前一个运算符的位置
                }else if( i == s.length()-1 || isSymbol(s.charAt(i+1)+"") ){
                    each = start == 0 ? s.substring(start,i+1) : s.substring(start+1,i+1);
                    if(isNumber(each)) {
                        data.add(each);
                        continue;
                    }
                    throw new RuntimeException("data not match number");
                }
            }
            //如果栈里还有元素，此时元素需要依次出栈入列，可以想象栈里剩下栈顶为/，栈底为+，应该依次出栈入列，可以直接翻转整个stack 添加到队列
            Collections.reverse(stack);
            data.addAll(new ArrayList<>(stack));

//        System.out.println(data);
            return data;
        }

        /**
         * 算出结果
         * @param list
         * @return
         */
        public static Double doCalc(List<String> list){
            Double d = 0.0;
            if(list == null || list.isEmpty()){
                return null;
            }
            if (list.size() == 1){
                result=list;
                d = Double.valueOf(list.get(0));
                return d;
            }
            ArrayList<String> list1 = new ArrayList<>();
            for (int i = 0; i < list.size(); i++) {
                list1.add(list.get(i));
                if(isSymbol(list.get(i))){
                    Double d1 = doTheMath(list.get(i - 2), list.get(i - 1), list.get(i));
                    list1.remove(i);
                    list1.remove(i-1);
                    list1.set(i-2,d1+"");
                    list1.addAll(list.subList(i+1,list.size()));
                    break;
                }
            }
            doCalc(list1);
            return d;
        }

        /**
         * 运算
         * @param s1
         * @param s2
         * @param symbol
         * @return
         */
        public static Double doTheMath(String s1,String s2,String symbol){
            Double result=0.0 ;
            switch (symbol){
                case ADD : result = Double.valueOf(s1) + Double.valueOf(s2); break;
                case MINUS : result = Double.valueOf(s1) - Double.valueOf(s2); break;
                case TIMES : result = Double.valueOf(s1) * Double.valueOf(s2); break;
                case DIVISION :
                    if(Double.valueOf(s2)==0){
                    result=null;break;
                }else
                    result = Double.valueOf(s1) / Double.valueOf(s2); break;
                default : result = null;
            }
            return result;

        }


              void fCalcuate(){
                  try {
                      //开头为负得处理
                      if (math.charAt(0)=='-')
                          math="0"+math;
                      //处理开头为括号
                      if(math.charAt(0)=='(')
                          math="0+"+math;
                      doCalc(doMatch(math));

                      restult=result.get(0);
                  } catch (Exception e) {
                      e.printStackTrace();
                  }
          }

    }
